When exploring for or extracting subterranean resources, such as oil, gas, or geothermal energy, and in similar endeavors, it is common to form boreholes in the earth. Such boreholes are often formed by engaging the earth with a rotating drill bit capable of degrading tough earthen materials. As rotation continues the borehole may elongate and the drill bit may be fed into it on the end of a drill string.
At times it may be desirable to take measurements or perform various functions within a borehole while drilling is in progress. It is believed that certain measurements and functions are most effective when taken or performed as close as possible to an end of a drill string, or on a drill bit itself. Drill bits of this type, however, often experience significant wear and damage while drilling, due to the harsh conditions. Worn or damaged drill bits often require replacement which can be expensive and time consuming. Instrumenting drill bits to take measurements or perform functions may significantly add to replacement expense and complexity.
One of the more complex aspects of instrumenting such a drill bit is providing a mechanism for communicating back and forth across the connection between the drill bit and the drill string. Such connections are typically made by threading a drill bit to a drill string amid an often dirty and hectic drilling operation. Given the disorder of such conditions it may be difficult to certify the final positions, either rotationally or axially, of the drill bit relative to the drill string. Any communication mechanism spanning such a connection must be robust and functional regardless of orientation.
Another feature adding complexity to drill bit instrumentation is the externally-threaded protrusions and the internally-threaded cavities that commonly form either side of the connection. In particular, passing communications into a cavity may be difficult as access may be restricted by space constraints. Thus, a mechanism capable of passing communications across a drill-string-to-drill-bit connection independent of specific rotational orientation while providing access inside a threaded cavity may prove useful in instrumenting a drill bit.